Contribution to Knowledge on Bioapatites: Does Mg Level Reflect the Organic Matter and Water Contents of Enamel?

The matter constituting the enamels of four types of organisms was studied. The variability of the ions was presented in molar units. It was proven that the changes in water contents of the enamel are significantly positively related to changes in Mg; inversely, there is also a strong connection with changes in Ca and P, the main components of bioapatite. The variability in the organic matter has the same strong and positive characteristics and is also coupled with changes in Mg contents. Amelogenins in organic matter, which synthesize enamel rods, likely have a role in adjusting the amount of Mg, thus establishing the amount of organic matter and water in the whole enamel; this adjustment occurs through an unknown mechanism. Ca, P, Mg, and Cl ions, as well as organic matter and water, participate in the main circulation cycle of bioapatites. The selection of variations in the composition of bioapatite occurs only along particular trajectories, where the energy of transformation linearly depends on the following factors: changes in the crystallographic d parameter; the increase in the volume, V, of the crystallographic cell; the momentum transfer, which is indirectly expressed by ΔsinΘ value. To our knowledge, these findings are novel in the literature. The obtained results indicate the different chemical and crystallographic affinities of the enamels of selected animals to the human ones. This is essential when animal bioapatites are transformed into dentistic or medical substitutes for the hard tissues. Moreover, the role of Mg is shown to control the amount of water in the apatite and in detecting organic matter in the enamels.

Quantitative Description of Isomorphism in the Series of Simple Compounds

The introduction of the notion of energy change resulting from the ion exchange in apatites leads to the question: how can some simple isomorphic series be described using the mentioned idea? We concentrated on the simple isomorphic series of compounds: apatite, bioapatite, calcite, aragonite, celestine, K-, Zn- and Cu-Tutton's salts. It was demonstrated in all the series, except Tutton's salts, that the change in energy and the change in the crystal cell volume are, in a simple way, dependent on the change in the ionic radii of the introduced ions. The linear relationships between the variations in energy and in the universal crystallographic dimension d were derived from the earlier equations and proven based on available data. In many cases, except the Tutton's salts, linear dependence was discovered between the change in energy and the sinus of universal angle Θ, corresponding to the change in momentum transfer. In the same cases, linear dependencies were observed between the energy changes and the changes in the volumes of crystallographic cells, and mutually between changes in the crystallographic cell volume V, crystallographic dimension d, and diffraction angle Θ.

Studies on Chemical Composition, Structure and Potential Applications of Keratoisis Corals

The chemical composition and structure of bamboo octocoral Keratoisis spp. skeletons were investigated by using: Scanning Electron Microscopy SEM, Raman Microscopy, X-ray Diffraction XRD, Laser Ablation-Inductively Coupled Plasma LA-ICP, and amino acid analyzers. Elements discovered in the nodes (mainly organic parts of the skeleton) of bamboo corals showed a very interesting arrangement in the growth ring areas, most probably enabling the application of bamboo corals as palaeochronometers and palaeothermometers. LA-ICP results showed that these gorgonian corals had an unusually large content of bromine, larger than any other organism yet studied. The local concentration of bromine in the organic part of the growth rings of one of the studied corals grew up to 29,000 ppm of bromine. That is over 440 times more than is contained in marine water and 35 times more than Murex contains, the species which was used to make Tyrian purple in ancient times. The organic matter of corals is called gorgonin, the specific substance that both from the XRD and Raman studies seem to be very similar to the reptile and bird keratins and less similar to the mammalian keratins. The missing cross-linking by S-S bridges, absence of aromatic rings, and significant participation of β-turn organization of peptides differs gorgonin from keratins. Perhaps, the gorgonin belongs to the affined but still different substances concerning reptile and bird keratin and in relation to the more advanced version-the mammalian one. Chemical components of bamboo corals seem to have great medical potential, with the internodes as material substituting the hard tissues and the nodes as the components of medicines.

Hierarchy of Bioapatites

Apatites are one of the most intensively studied materials for possible biomedical applications. New perspectives of possible application of apatites correspond with the development of nanomaterials and nanocompounds. Here, an effort to systematize different kinds of human bioapatites forming bones, dentin, and enamel was undertaken. The precursors of bioapatites and hydroxyapatite were also considered. The rigorous consideration of compositions and stoichiometry of bioapatites allowed us to establish an order in their mutual sequence. The chemical reactions describing potential transformations of biomaterials from octacalcium phosphate into hydroxyapatite via all intermediate stages were postulated. Regardless of whether the reactions occur in reality, all apatite biomaterials behave as if they participate in them. To conserve the charge, additional free charges were introduced, with an assumed meaning to be joined with the defects. The distribution of defects was coupled with the values of crystallographic parameters “a” and “c”. The energetic balances of bioapatite transformations were calculated. The apatite biomaterials are surprisingly regular structures with non-integer stoichiometric coefficients. The results presented here will be helpful for the further design and development of nanomaterials.

Studies of Peculiar Mg-Containing and Oscillating Bioapatites in Sheep and Horse Teeth

New types of biological apatites have been discovered in molar sheep and horse teeth and are divided in two types. In the first and more general type, the release of Mg ions is parallel to the changes in composition of apatite leading to a final stoichiometric ratio of Ca to P ions, going from dentin depth towards the boundary of enamel with air. Inside dentin, another apatite sub-types were discovered with alternating layers of Mg-rich and C-rich apatites. The approximate formal stoichiometric relationships for these peculiar types of bioapatites are suggested. We identified two kinds of ion-exchanges responsible for formation of peculiar apatites. Various combinations of main and minor elements lead to new versions of biological apatites.

Novel Approach to Tooth Chemistry: Quantification of Human Enamel Apatite in Context for New Biomaterials and Nanomaterials Development

A series of linear profiles of the elements of the enamel in human molar teeth were made with the use of an electron microprobe and a Raman microscope. It is postulated that the enamel can be treated as the superposition of variable "overbuilt" enamel on the stable "core" enamel at the macro-, micro- and nanoscale level. The excessive values characterize the "overbuilt enamel". All the profiles of excessive parameters along the enamel thickness from the enamel surface to the dentin enamel junction (DEJ) can be approximated very precisely with the use of exponential functions, where Ca, P, Cl and F spatial profiles are decaying while Mg, Na, K and CO32- ones are growing distributions. The "overbuilt" apatite formed on the boundary with DEJ, enriched in Na, Mg, OH and carbonates, reacts continuously with Ca, Cl and F, passing into an acid-resistant form of the "overbuilt" enamel. The apparent phases arriving in boundary regions of the "overbuilt enamel" were proposed. Microdiffraction measurements reveal relative variation of energy levels during enamel transformations. Our investigations are the milestones for a further new class of biomaterial and nanomaterial development for biomedical applications.

Analysis of psychoactive and intoxicating substances in legal highs

"Legal highs" known also as "smarts", "legal drugs" or "boosters" contain in their composition psychoactive substances the production, sale and possession of which are not prohibited in legislation. They are offered for sale under the cover of collectors' items, a salt bath, aroma sticks, or plant fertilizer. Marketing was the reason for such high sales of these "highs" in Poland. The phenomenon became of concern when information became available about the first cases of tragic health consequences. Raising the awareness of youth about the level of imminent danger and serious consequences associated with the use of legal highs may be a very effective way to develop appropriate attitudes of young people, and in the light of their own health can help them take proper life decisions."Legal highs" are substances of natural or synthetic origin having psychostimulating properties. These compounds may differ in chemical structure, potency, half-life, metabolism and severity of side effects. Their pharmacological activity is associated with changes in the neurotransmitter system. After higher doses of "legal highs" psychotic symptoms may occur: visual and auditory hallucinations resembling schizophrenic endogenous psychoses. An alarming fact is the underestimation of the adverse effect of these substances on human health. Any actions aimed at improving this situation are extremely important; therefore, in one of the key projects undertaken at the Institute of Rural Health in Lublin, in cooperation with other scientific institutes, concerned the analysis of a selected series of "legal highs". This research was meant top serve as a source of information for science and medicine, and for popularizing knowledge about legal highs.

Analysis of composite structure and primordial wood remains in petrified wood

Among all the fossils, petrified wood belongs to the most impressive and most common of materials. Still, its study has not exceeded the purely phenomenological level. The recognition of the conserved structure of petrified wood seems to be of meaning for understanding the geological past, the complete carbon cycle inside the Earth, and the structure of potential new materials. The first ever published spatial distributions of the remains of the primordial organic material (lignin, cellulose, pectins) in the cells of permineralized wood, from Dunarobba (Central Italy), are presented here. They were collected using micro-Raman spectrometry. The composite nature of the petrified material (calcite located in the lumena of cells and goethite located in the cell walls) was confirmed by electron, proton, and X-ray microprobes. The structure of the cell walls was well preserved. The mineralization process was induced by the tracheidal water flow and was stopped after formation of pipe-like goethite shielding of the cell walls on the cellulose scaffolds. The chemical (Eh and pH ranges) and probable microbial conditions for such a pattern of mineralization were determined. We estimate that substantial amounts of the primordial organic matter were preserved in bodies of petrified wood on a global scale. The wood petrifaction process, if well understood, can be a basis for the production of "everlasting" organic-inorganic composite compounds.

Scheme for x-ray tracing in capillary optics

A set of trigonometric equations is derived for deterministic x-ray tracing in capillaries. A variety of capillary shapes is encompassed by this approach. The resulting reflectivity coefficients, gain factors, and angular beam divergence are determined. The results can also be applied to the case of neutron and proton guiding in narrow pipes.